Can we really restyle vector tile maps? Attributes stripped out.

[NathanMellor]

Vector Tiled maps show promise of allowing you to style them later in different ways. 

However, that doesn't actually work, does it?

I have observed that ArcGIS PRO, when creating a vector tile package, strips all attributes it doesn't think it needs for the style defined on the map in ArcGIS PRO. 

For size, this is a good optimization. But we do not have control over what attributes are kept. 

In addition, it also changes the attributes it does keep to have names and value ranges of its own choosing. 

For example, there may a rule to apply a certain style to a line if height%100 =0. 

The resulting vector tile will have something like: 

"_symbol": "1"

Making the attributes unrecognizable to anyone who would want to create changes to the style. 

What this means is that we would have to anticipate every possible style rule before exporting a Vector Tile Package. You could change colors later, but that is about all.  

If you colored all roads green, and later want to make the major freeways yellow and bolder, you are out of luck. 

So maybe you would want to get your first style right, and then come back to ArcGIS PRO to restyle, create a new style, and then export the style without exporting all the tiles again. But you can't do that either. 

If you managed to find a perfect style in mapbox vector style specification, you would have to reverse engineer all its rules and try to recreate them in ArcGIS Pro. 

I'll note that there are tools out there, even open source ones, that can create vector tiles in a more predictable fashion.  

However, ESRI has worked really hard to make sure that the server or runtime does not work with any vector tiles not created by ArcGIS PRO. 

Am I correct, or is there something I am missing?

[DanPatterson_Retired]

Author a map for vector tile creation....

Under Retain Relevant Attribution

There is a whole section on bringing other field information in... and they point to...

To bring specific fields into the vector tiles, highlight them in the Fields view of the layer.

Are you saying that this doesn't work? or that it isn't obvious how to do it? or it is too complicated?  Not sure I caught your whole concern, or even if this section applies

[NathanMellor]

Last time I read that article, I may not have looked deeply enough at Retain Relevant Attribution, because I may have assumed it meant "Keep Copyright Notices". The word attributions is used to mean that in other documentation:

Attribution | API Reference | ArcGIS API for JavaScript 3.23  

I will try it, because I think it is what I am looking for. 

If the schema is predictable, I can also work on the style independently of the data. 

[DanPatterson_Retired]

an easy assumption to make.....

attribution... leverage....

it seems that the secondary/tertiary meanings of words are used quite a lot in current parlance ....

the hashtag writing style and era I suppose

[NathanMellor]

There is one remaining issue in creating new styles. 

We don't appear to have any control over how the sprite.json and sprite.png are generated. 

I don't know how to make sure symbols make it in if not all symbols are used in the first style published. 

In other words, no known equivalent to what we did to retain fields in order to retain symbols. 

If I had a designer create a custom sprite page, I would have to have to manually insert it into the VTPK before upload. 

I thought perhaps that I could point the style to a different sprite link - perhaps a content item I upload to ArcGIS Online. It won't allow me to upload a .json, although it does accept a .png. 

If I hosted a new sprite.png and sprite.json on my own domain, will that cause cross domain problems?

And will they still get included in offline vector downloads?